JP4698514B2 - Key switch device and keyboard - Google Patents

Description

  The present invention relates to a key switch device that is operated to make a keystroke, and more particularly to a key switch device that is mounted on a keyboard that is an input device of an electronic device. Furthermore, the present invention relates to a keyboard provided with a plurality of such key switch devices.

  In thin and low-profile keyboards equipped in portable electronic devices such as notebook and palmtop personal computers, the operability and structure of the key switch device that is key-operated is promoted to be low. There is a need to improve reliability. In general, a key switch device that can be used for a low-profile keyboard has a base, a key top disposed above the base, and a key top that guides and supports the base in the ascending / descending direction (ie, substantially vertical). A pair of link members, a switch member having a contact portion that opens and closes in response to the raising and lowering operation of the key top, and an urging member that applies an elastic urging force in the upward direction (that is, initial position returning force) to the key top. It is prepared for. The key top can be moved up and down while maintaining a predetermined posture in a substantially vertical direction with respect to the base by the pair of link members interlocking with each other.

  Conventionally, this type of key switch device is of a so-called gear link type in which the pair of link members are combined in an inverted V shape in side view and meshed with each other in a gear shape in one end region thereof (see, for example, Patent Document 1). In addition, a so-called pantograph type that is combined in an X shape in a side view and is connected to each other so as to be rotatable or slidable is employed (see, for example, Patent Document 2). In addition, as the switch member, a sheet-like switch (referred to as a membrane switch sheet in the present application) having a pair of flexible circuit boards that carry a pair of contacts constituting an openable / closable contact portion facing each other is widely used. It has been adopted.

  The key switch device further includes an actuating member that opens and closes the contact portion of the switch member in response to the lifting operation of the key top. For example, in the key switch device disclosed in Patent Document 1, a rubber dome-shaped actuating member disposed between a key top and a membrane switch sheet is used. When the key top reaches the lower limit position of the lifting / lowering operation, the operating member presses the membrane switch sheet on the inner surface of the dome top portion to close the contact portion. Further, the dome-shaped actuating member also functions as the aforementioned urging member that elastically deforms as the key top descends and applies an initial position return force to the key top. In this key switch device, when the key top is pressed, the actuating member (biasing member) elastically deforms in a buckling manner due to its own dome shape, thereby non-linearly corresponding to the pressing displacement amount of the key top. An elastic biasing force is exerted on the key top, thereby ensuring a unique keystroke characteristic with a so-called click feeling.

  By the way, since the use environment of the keyboard which is the input device of the electronic device is diversified, the internal structure (electrical contact portion, elevating guide portion, etc.) of a plurality of key switch devices mounted on the keyboard is made of dust, liquid, etc. It is required to equip the keyboard with a protective structure for protecting against the entry of foreign objects. As this type of protective structure, a retrofit type cover that covers the entire keyboard layout surface is known. However, the presence of the cover deteriorates the keystroke operability and finger feel of each key switch device. There is concern. Therefore, a configuration in which a protection function against foreign substance intrusion is incorporated in the key switch device itself has been proposed.

  For example, in Patent Document 3, in a key switch device having a key top that is slidably guided in a vertical direction with respect to a base, a sliding guide structure for the key top (a cylindrical guide provided at the base and a key top are provided. A configuration is disclosed in which a protective member (cup rubber) for preventing dust and liquid from entering the electric circuit in the base through a gap of the base and the key top is provided between the base and the key top. In this key switch device, the cup rubber is a cylindrical element that can be elastically deformed in accordance with the downward movement of the key top, and always surrounds the sliding guide structure during the upward and downward movement of the key top, Prevent ingress of dust and liquid. The cup rubber also functions as a biasing member that applies an initial position returning force in the upward direction to the key top by its own elastic restoring force.

JP 2003-031067 A JP 2002-231090 A Japanese Patent Laid-Open No. 10-063394

  The key switch device described in Patent Document 3 described above has a sliding guide type key top that is frequently used in a keyboard of a normal size that is not low profile. The built-in cup rubber functions as a biasing member for returning the initial position of the key top, and surrounds the columnar sliding guide structure composed of the base cylindrical guide and the key top slider. Is done. In this configuration, the area to be protected against foreign object intrusion is the gap between the cylindrical guide and the slider and is relatively narrow. Therefore, the protection function required for the cup rubber is not so strict, and therefore the biasing force is not required. Diversion as a member is possible.

  However, for example, in the key switch device for a low-profile keyboard described in Patent Document 1 or Patent Document 2 described above, a pair of links in which the key-top guide support structure is interlocked with each other in an openable manner with the interconnection portion as the center. Since the movable portion is formed of a member, the movable portion exists in a relatively wide range between the base portion and the key top, and a gap that can communicate with the contact portion of the switch member (for example, an engagement portion between the base portion and the link member, The interaction portion between the contact portion and the operating member is also formed in a relatively wide range of the base portion. If foreign matter such as dust or liquid enters the movable part of the link member or the part where the base part and the link member are engaged, there is a risk that the keystroke characteristics of the key top will be affected. There is a concern that the accuracy of the contact opening / closing operation is reduced when a foreign substance enters the part that interacts with the member. Therefore, a key switch device for a low-profile keyboard is required to have a stricter protection function against the entry of foreign matter into the internal structure.

An object of the present invention is to provide a key switch device having a pair of link members that guide and support the key top in the ascending / descending direction with respect to the base, and has a protective function that can reliably and stably prevent the entry of foreign matter into the internal structure. To provide a key switch device.
Another object of the present invention is to provide a low-profile keyboard having a plurality of key switch devices as described above and having excellent operability and structural reliability.

  In order to achieve the above object, a first aspect of the present invention includes a base, a key top disposed above the base, and a pair of links that guide and support the key top in the up and down direction relative to the base. In a key switch device comprising: a member; a switch member having a contact portion that opens and closes in response to a lifting operation of the key top; and a biasing member that applies an elastic biasing force to the key top in the upward direction. The contact portion and the biasing member are inserted between the base portion and the key top at a position surrounding the contact portion and the biasing member, and are deformed following the lifting and lowering operation of the key top. There is provided a key switch device characterized by comprising a protective member that protects against the intrusion.

  According to a second aspect of the present invention, in the key switch device according to the first aspect, the protection member can be used to move the key top up and down without affecting the sense of keystroke operation obtained by the elastic biasing force of the biasing member. Provided is a key switch device having a characteristic of following and deforming.

  According to a third aspect of the present invention, in the key switch device according to the first or second aspect, the base portion has a sliding support portion that slidably supports each of the pair of link members, and the protection member includes: Provided is a key switch device that contacts the upper surface of a base at its lower end to protect the sliding support from entry of foreign matter.

  According to a fourth aspect of the present invention, in the key switch device according to any one of the first to third aspects, the key top has a rotation support portion that rotatably supports each of the pair of link members. The protective member provides a key switch device that contacts the inner surface of the key top at the upper end thereof and protects the rotation support portion from intrusion of foreign matter.

  According to a fifth aspect of the present invention, in the key switch device according to any one of the first to fourth aspects, when the key top is at the upper limit position of the lifting / lowering operation, the protective member is separated from the base and the key top. A key switch device is provided that is subjected to an initial pressure.

  According to a sixth aspect of the present invention, in the key switch device according to any one of the first to fifth aspects, the switch member carries a contact portion below the key top and is disposed adjacent to the base portion. A switch sheet is provided, and the urging member is disposed between the key top and the membrane switch sheet, and is elastically deformed to generate an elastic urging force as the key top is lowered, and the key top is in a lower limit position for the raising / lowering operation. A key switch device is provided that closes the contact portion by pressing the membrane switch sheet when reaching the position.

  A seventh aspect of the present invention is the key switch device according to any one of the first to sixth aspects, wherein the pair of link members includes gear teeth meshing with each other at one end region, and a key top. A key switch device is provided that includes a pivot shaft that is pivotably coupled to the base portion, and a sliding pivot shaft that slidably engages with a base portion at each other end region.

  The invention according to claim 8 is a keyboard configured by arranging a plurality of key switch devices according to any one of claims 1 to 7, each of the protection members of the plurality of key switch devices. Provides a keyboard characterized by integrally including a sheet member extending in a range including the key switch devices.

  The invention according to claim 9 is a keyboard configured by arranging a plurality of the key switch devices according to any one of claims 1 to 7, and each of the protection members of the plurality of key switch devices. Is fixed to a sheet member extending in a range including these key switch devices.

  According to the first aspect of the present invention, the protective member is a member different from the urging member that is similarly deformed following the up-and-down movement of the key top. Therefore, it is possible to prepare a protective member having an optimum characteristic capable of exhibiting a necessary level of foreign substance intrusion preventing function. Therefore, in a key switch device having a pair of link members interlocking with each other as a key top guide structure so as to be suitably used for a low-profile keyboard, it is possible to reliably and stably prevent foreign matter from entering the internal structure. Stricter protective functions that can be ensured. As a result, a key switch device with excellent operability and structural reliability that can prevent the key-top operation characteristics of the key top from being affected by the presence of foreign matter and the accuracy of the opening / closing operation of the contact point from being lowered. Is provided. In addition, since the key switch device according to the present invention can be configured only by adding a protective member to the conventional low-profile key switch device, an increase in manufacturing cost can be suppressed.

  According to the second aspect of the present invention, the influence on the keystroke operation characteristics of the key switch device is eliminated (that is, the operation is performed by the operator) even though the protective member is interposed between the base portion and the keytop. High level of protection against foreign objects can be secured without giving the above feeling of strangeness.

  According to the third aspect of the present invention, the sliding support portion provided on the base portion is reliably protected from the intrusion of the foreign matter during the lifting operation of the key top. It is possible to prevent the influence on the contact point and the accuracy of the opening / closing operation of the contact point from being lowered.

  According to the fourth aspect of the present invention, the rotation support portion provided on the key top is surely protected from the intrusion of the foreign matter during the raising and lowering operation of the key top. It is possible to prevent the characteristics from being affected.

  According to the fifth aspect of the present invention, since the protection member is stably held in a state of being elastically deformed between the base portion and the key top even when the key switch device is not used, the protection member and the base portion The problem of foreign matter entering through the gap is avoided.

  According to the sixth aspect of the present invention, in the configuration in which the switch member includes the membrane switch sheet, the contact portion is reliably protected from the intrusion of foreign matters during the lifting and lowering operation of the key top.

  According to the seventh aspect of the present invention, in the configuration in which the pair of link members have a so-called gear link structure, the rotation support shaft and the slide support shaft are reliably protected from the intrusion of foreign matters during the key top lifting operation. Protected.

  According to the invention described in claim 8 or 9, a low-profile keyboard with excellent operability and structural reliability is provided.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. Corresponding components are denoted by common reference symbols throughout the drawings.
Referring to the drawings, FIG. 1 is an exploded perspective view of a key switch device 10 according to an embodiment of the present invention, FIG. 2 is an assembled sectional view when the key switch device 10 is not operated, and FIGS. 3 and 4 are key switch devices 10. FIG. 5 is an assembled cross-sectional view of the key switch device 10 during keystroke operation. The key switch device 10 can be suitably applied to a thin or low-profile keyboard equipped in a portable electronic device such as a notebook or palmtop personal computer.

  As shown in FIGS. 1 and 2, the key switch device 10 includes a base 12, a key top 14 disposed above the base 12, and the key top 14 in the ascending / descending direction relative to the base 12 (that is, substantially A pair of link members 16 that are guided and supported in the vertical direction), a switch member 20 having an electrical circuit contact portion 18 that opens and closes in response to the lifting and lowering operation of the key top 14, and the key top 14 with elasticity in the upward direction. And an urging member 22 that applies urging force (that is, initial position returning force). The key top 14 can be moved up and down while maintaining a predetermined posture in the vertical direction with respect to the base 12 by the pair of link members 16 interlocking with each other.

  The base portion 12 is a flat first plate having rigidity that serves as a structural basis of the key switch device 10 such as an independent metal thin plate made of a sheet metal material or a resin lower panel of a keyboard incorporating the key switch device 10. A support plate 24 and a frame-like second support plate 26 that is disposed on the first support plate 24 and is made of, for example, an integrally molded product of a resin material are provided. The second support plate 26 includes a substantially rectangular opening 28 that is substantially shielded by the key top 14, and a pair of sliding support portions 30 are provided along a pair of opposed inner peripheral edges that define the opening 28. , And are separated from each other in the link sliding direction (left-right direction in FIG. 2). Each sliding support portion 30 has a wall portion 30a extending in a bowl shape from the upper surface 26a of the second support plate 26 to above the opening portion 28, and the upper surface 26a is inside the longitudinal ends of the wall portion 30a. The guide grooves 32 extending substantially parallel to each other are formed. A pair of guide grooves 32 provided in each sliding support portion 30 slidably receives a first end (that is, lower end) region, which will be described later, of each link member 16.

  Note that the base 12 may be configured such that the second support plate 26 is omitted and the first support plate 24 directly guides and supports the link members 16 instead of the above configuration. In this case, a sliding support part (not shown) having a guide hole for slidingly guiding the first end (lower end) region of each link member 16 on the upper surface 24a of the first support plate 24 is the above-mentioned sliding. It is provided instead of the support part 30. Further, as will be described later, the base 12 can be provided with a light emitting structure for illuminating a symbol area such as a character or a code provided on the key top 14 from the inside of the key.

  The key top 14 is a substantially rectangular dish-like member made of an integrally molded product of, for example, a resin material. The key top 14 has an operation surface 14a that is key-operated by an operator, and an inner surface 14b opposite to the operation surface. A link support member 34 that rotatably supports a second end (that is, upper end) region of the link member 16 to be described later is attached. As shown in FIG. 3, the link support member 34 has two pairs of bearing holes (that is, rotation support portions) that receive support shafts (described later) provided in the second end regions of the pair of link members 16. 36 is provided. The link support member 34 is fixedly installed on the inner surface 14b of the key top 14 such that the two pairs of bearing holes 36 are oriented so as to be separated from each other in the link sliding direction (left-right direction in FIG. 2). Further details of the link support member 34 will be described later.

  The key top 14 may be configured such that the link support member 34 is omitted and the inner surface 14b is directly connected to both the link members 16 instead of the above configuration. In this case, a rotation support portion (not shown) that rotatably receives the second end (upper end) region of each link member 16 is formed on the inner surface 14 b of the key top 14 in place of the bearing hole 36. The

  The pair of link members 16 have the same shape and size as each other, and are combined so as to be connected to each other in a gear shape at one end thereof so as to exhibit an inverted V shape in a side view. Each link member 16 is made of, for example, an integrally molded product of a resin material. As shown in FIG. 4, a pair of arms 38 and 40 extending substantially parallel to each other and a body 42 that connects the arms 38 and 40 to each other are integrated. Prepare for. In the illustrated embodiment, in each link member 16, the end regions of both arms 38 and 40 including the body 42 are defined as the first end (ie, lower end) region of the link member 16, and both arms extended from the body 42. The distal end regions 38 and 40 are defined as the second end (ie, upper end) region of the link member 16.

  In the first end region of each link member 16, a pair of sliding support shafts 44 project from the outer surfaces of the arms 38, 40 that are separated from each other on the opposite side to the body 42 in a coaxial manner. Further, in the second end region of each link member 16, a pair of rotational support shafts 46 project from the outer surfaces of both arms 38 and 40 on the same side as the sliding support shaft 44 so as to be coaxial with each other. Both the sliding support shaft 44 and the rotation support shaft 46 have a cylindrical shape. Further, one arm 38 of each link member 16 is provided with one tooth 48 on the distal end surface of the second end region adjacent to the rotation support shaft 46, and the other arm 40 has a rotation support shaft. Two teeth 50 are provided on the distal end surface of the second end region close to 46.

  Each link member 16 slidably fits a pair of sliding support shafts 44 in the first end region into a corresponding guide groove 32 of the sliding support portion 30 provided on the second support plate 26 of the base portion 12. In addition, the pair of pivot support shafts 46 in the second end region are rotatably fitted in corresponding bearing holes 36 provided in the link support member 34 of the key top 14, so that the base 12 and the key top 14 are interposed between them. Be placed. At this time, in the pair of link members 16, one tooth 48 of each one arm 38 and two teeth 50 of each other arm 40 are engaged with each other to form an interlocking structure. The arms 38 and 40 can rotate in conjunction with each other about the respective rotation axis 52 (FIG. 1) defined by the rotation support shaft 46 of both arms 38 and 40.

  Therefore, the key top 14 swings in the opposite direction in synchronism with the rotation axis 52 (that is, the rotation engagement point between the rotation support shaft 46 and the bearing hole 36) of the pair of link members 16 as the center. Each of the first end regions slides in a substantially horizontal direction under guiding action by the corresponding sliding support portion 30 of the base portion 12 (that is, under sliding engagement between the sliding support shaft 44 and the guide groove 32). The operation surface 14a is translated in a substantially vertical direction with respect to the base 12 while maintaining a predetermined substantially horizontal posture in which the operation surface 14a is disposed substantially parallel to the upper surface 26a of the base 12 (second support plate 26). The upper limit position of the keystroke stroke of the key top 14 (that is, the stroke of the lifting / lowering operation) is such that the sliding of the first end regions of the pair of link members 16 in the mutual approach direction of the corresponding sliding support portion 30 of the base portion 12 is performed. It is defined when it is locked by the peripheral wall of each guide groove 32 (see FIG. 2). As the key top 14 is lowered from the upper limit position, the first end regions of the link members 16 are mutually orthogonal to the ascending / descending direction of the key top 14 under the guiding action of the guide groove 32 with respect to the sliding support shaft 44. Slide in the away direction. When the key top 14 reaches the lower limit position of the key stroke, the contact portion 18 of the switch member 20 is closed as will be described later (see FIG. 4).

  The switch member 20 includes a membrane switch sheet 54 that supports the contact portion 18 at a position below the key top 14 and is disposed adjacent to the base portion 12. Although not shown, the membrane switch sheet 54 is a sheet that holds a pair of flexible circuit boards that carry a pair of contacts facing each other, and supports the circuit boards at a predetermined interval and keeps both contacts open. The contacts formed by patterning on the surfaces of the film bases of both circuit boards constitute the contact portion 18 of the switch member 20. The membrane switch sheet 54 is inserted and supported between the first support plate 24 and the second support plate 26 of the base portion 12, and the contact portion 18 is positioned substantially at the center of the opening 28 of the second support plate 26. The

  The urging member 22 is a dome-shaped member integrally formed from a rubber material, and is disposed between the key top 14 and the membrane switch sheet 54 with the dome top portion 22a facing the key top 14 side. The urging member 22 is disposed in the opening 28 of the second support plate 26 of the base 12 at the dome opening end 22 b at the lower end thereof, and is fixed to the membrane switch sheet 54. The urging member 22 is arranged such that the dome top portion 22a is spaced upward from the membrane switch sheet 54 when no load is applied. A protrusion 22c is formed on the inner surface of the dome top portion 22a of the biasing member 22 so as to align with the contact portion 18 of the membrane switch sheet 54 and press and close the contact portion 18 when the key top 14 is lowered. The

  In the key switch device 10, when no external force is applied to the key top 14, the urging member 22 urges and supports the key top 14 at the stroke upper limit position vertically away from the base 12 by the dome top 22a (FIG. 2). At this time, the membrane switch sheet 54 is in a state where the contact portion 18 is opened. When the key top 14 is pushed down by a keystroke operation, the urging member 22 is elastically deformed as the key top 14 is lowered, and an upward elastic urging force (initial position restoring force) is applied to the key top 14. In addition, when the key top 14 reaches the stroke lower limit position, the membrane switch sheet 54 is pressed from the outside by the protrusion 22c on the inner surface to close the contact portion 18 (FIG. 4). When the pressing force on the key top 14 is released, the urging member 22 is elastically restored to return the key top 14 to the upper limit position, and the membrane switch sheet 54 is restored to open the contact portion 18. The Thus, the urging member 22 also functions as an operating member that opens and closes the contact portion 18 of the switch member 20 in response to the lifting and lowering operation of the key top 14.

  When the key top 14 is pressed, the urging member 22 is elastically deformed in a buckling shape due to its own dome shape, and thereby an elastic urging force nonlinearly corresponding to the pressing displacement amount of the key top 14 is applied to the key top 14. It is designed to affect the top 14. As a result, in the key switch device 10, when the pressing displacement amount of the key top 14 exceeds a predetermined value, the so-called click feeling that the urging force in the returning direction that has been gradually increased until then suddenly decreases is provided. Accompanied by the unique keystroke operation characteristics.

  The key switch device 10 itself has a protective function for preventing foreign matters such as dust and liquid from entering the switch internal structure (link member 16, switch member 20, etc.) reliably and stably. ing. More specifically, the key switch device 10 is inserted between the base 12 and the key top 14 at a position surrounding the pair of link members 16, the contact portion 18 of the switch member 20, and the biasing member 22. A protective member 56 is provided. The protection member 56 is a rubber annular element that can be elastically deformed as the key top 14 is lowered, and is elastically deformed between the base 12 and the key top 14 following the lifting and lowering operation of the key top 14. Thus, the posture that always surrounds the pair of link members 16, the contact portion 18, and the biasing member 22 is maintained. Thereby, the protection member 56 reliably and stably protects the link member 16, the contact portion 18 and the urging member 22 from the intrusion of foreign matters during the raising / lowering operation of the key top 14 (see FIGS. 2 and 4).

  The protection member 56 includes a cylindrical portion 58 having a substantially rectangular shape in plan view that exhibits a main protection function against foreign matter, and a sheet-like portion 60 connected to one end (lower end in the drawing) of the cylindrical portion 58. The cylindrical portion 58 is provided with a step 58a whose radial dimension locally changes at an intermediate position in the height direction. In addition, the sheet-like portion 60 is formed with an opening 60 a that communicates with the internal space of the tubular portion 58. The cylindrical portion 58 and the sheet-like portion 60 of the protective member 56 can be integrally formed with each other, or can be formed as separate members and fixed to each other with an adhesive or the like (see FIGS. 2 and 5). , A protective member 56 formed by integrally molding the tubular portion 58 and the sheet-like portion 60).

  In the key switch device 10 having the above-described configuration, the protective member 56 is exclusively used as a member different from the biasing member 22 which is a rubber element that elastically deforms following the raising and lowering operation of the key top 14. Since it is equipped for the purpose of preventing foreign matter from entering the protective member 56, it is possible to prepare the protective member 56 having an optimum characteristic capable of exhibiting a necessary level of foreign matter intrusion preventing function. Therefore, in order to be suitably used for a low-profile keyboard, the guide structure of the key top 14 includes a pair of link members 16 that are interlocked with each other about the interconnection portion (the teeth 48 and 50 in the illustrated embodiment). In the key switch device 10 provided, a stricter protection function that can reliably and stably prevent the entry of foreign matter into the internal structure is ensured. As a result, a key excellent in operability and structure reliability that can prevent the keystroke operation characteristics of the key top 14 from being affected by the presence of foreign matter and the accuracy of the opening / closing operation of the contact portion 18 from being lowered. A switch device 10 is provided. Moreover, since the key switch device 10 according to the present invention can be configured only by adding the protective member 56 to the low-profile key switch device having the conventional structure, an increase in manufacturing cost can be suppressed.

  The protective member 56 is easily deformed by accurately following the lifting and lowering operation of the key top 14 without substantially affecting the sense of keystroke operation given by the elastic biasing force of the biasing member 22 applied to the keytop 14. It is very advantageous to have the following characteristics: In this case, the initial position return operation of the key top 14 is substantially controlled by the elastic restoring force generated by the biasing member 22. Such characteristics of the protection member 56 are obtained mainly depending on attributes such as the shape, size, material, and the like of the cylindrical portion 58. According to this configuration, despite the fact that the protective member 56 is interposed between the base portion 12 and the key top 14, the influence on the keystroke operation characteristics of the key switch device 10 is eliminated (that is, the operator can operate in the operational manner). A high level of protection against foreign objects can be ensured.

  The lower end of the cylindrical portion 58 and the seat portion 60 of the protective member 56 are in contact with the upper surface 26 a of the second support plate 26 on the outside of the pair of sliding support portions 30 provided on the second support plate 26 of the base 12. (Fig. 2). Thereby, the protective member 56 has the opening 28 of the base 12 for disposing the biasing member 22 adjacent to the contact portion 18 of the switch member 20 and the sliding of the base 12 for slidably supporting the link member 16. The support portion 30 (especially the guide groove 32) is always surrounded during the raising / lowering operation of the key top 14 to reliably protect against the intrusion of foreign matter. As a result, it is possible to prevent the presence of foreign matter from affecting the keystroke operation characteristics of the key top 14 and the accuracy of the opening / closing operation of the contact portion 18 from being lowered.

  Further, the protective member 56 is disposed such that the upper end 58b of the cylindrical portion 58 is in contact with the key top inner surface 14b outside the link support member 34 installed on the inner surface 14b of the key top 14 (FIG. 2). . As a result, the protection member 56 allows the link support member 34 (particularly the bearing hole (rotation support portion 36) 36) of the key top 14 for connecting the link member 16 to be rotatable, during the lifting and lowering operation of the key top 14. Always besiege to ensure protection from foreign objects. As a result, it is possible to prevent the presence of foreign matter from affecting the keystroke operation characteristics of the key top 14.

  Further, it is advantageous that the protective member 56 is placed in a state of receiving an initial pressure from the base portion 12 and the key top 14 when the key top 14 is at the upper limit position of the above-described lifting operation. According to such a configuration, even when the key switch device 10 is not used, the protection member 56 is stably held in a state of being slightly elastically deformed between the base portion 12 and the key top 14, and in particular, the seat. The portion 60 is prevented from being lifted or turned up with respect to the base 12, and a problem that foreign matter enters between the sheet-like portion 60 and the base 12 is avoided.

  The above-described protection member 56 is not limited to the illustrated key switch device 10 and can be suitably applied to, for example, a conventional key switch device having a so-called pantograph-type link member. Even in such a configuration, a key switch device excellent in operability and structural reliability is provided, which has a protective function capable of reliably and stably preventing the entry of foreign matter into the internal structure.

  In the key switch device 10, the link support member 34 provided on the key top 14 is erected substantially parallel to each other along a flat main plate portion 62 having a substantially rectangular shape in plan view and a pair of edges of the main plate portion 62. A pair of opposing wall portions 64 are provided, and two bearing holes 36 are formed in each opposing wall portion 64 (FIG. 3). The pair of opposing wall portions 64 are separated from each other by a distance that allows the above-described second end region (including the rotation support shaft 46) of each link member 16 to be inserted stably without substantial backlash. (See FIG. 6A). Further, each bearing hole 36 is formed as a through hole not having a notch that communicates with the peripheral edge of the opposing wall portion 64 to the outer edge of the bearing hole 36. Receiving smoothly rotating. The bearing hole 36 is preferably a circular hole as shown in the drawing, but may be a polygonal hole on the premise that smooth rotation of the rotation support shaft 46 is not hindered.

  By adopting the link support member 34 having the above-described configuration, the key switch device 10 has a conventional key switch in which a through hole with a notch is provided in a rotation support portion of a key top that rotatably connects the link member. Compared with the apparatus, the rotation support shaft 46 of the link member 16 is supported more stably in the bearing hole 36 of the link support member 34 while reliably preventing the drop off. Therefore, for example, even when an external force that pulls the key top 14 away from the base 12 is applied to the outer edge 14c (FIGS. 1 and 2) of the key top 14, the rotation of the link member 16 from the bearing hole 36 of the link support member 34. It is possible to reliably prevent the moving support shaft 46 from coming off. Further, when such an external force is excessive, the link support member 34 is detached from the key top 14, so that the link support member 34 can be prevented from being damaged. As a result, the key switch device 10 is excellent in operability and structural reliability that can prevent the key top 14 from dropping off unexpectedly.

  In order to prevent an external force such as pulling away from the base 12 from being unintentionally applied to the outer edge 14c of the key top 14, for example, as shown in FIG. An annular protrusion 66 that is spaced from the outer edge 14c of the key top 14 may be provided. Also in this case, the projection 66 and the sheet-like portion 60 may be integrally formed as illustrated, or the separate projection 66 may be fixed to the sheet-like portion 60 with an adhesive or the like.

  In order to assemble the key switch device 10 safely and easily, the link support member 34 has at least a main plate portion 62 and a pair of pivot shafts 46 of each link member 16 on a pair of opposing wall portions 64. It has elasticity so that it can be received in the corresponding bearing hole 36 provided. Hereinafter, the assembly work of the link member 16 to the link support member 34 in the assembly process of the key switch device 10 will be described.

  When the link support member 34 is in a normal state, the distance between the pair of opposing wall portions 64 is such that the distance between the outer surfaces of the arms 38 and 40 of the link member 16 allows the link member 16 and the opposing wall portion 64 to slide smoothly. The dimensions are set so as to be substantially equal within a range not hindering (FIG. 6A). When the key switch device 10 is assembled, the link support member 34 is assembled as a single unit to the second end region of the pair of link members 16. At this time, a pressing force F is further applied to the main plate portion 62 of the link support member 34 in a state where the outer edges of the opposing wall portions 64 of the link support member 34 are pressed against the pair of rotation support shafts 46 of the link members 16. (FIG. 6B). As a result, the main plate portion 62 is concavely curved outward, and the distance between the opposing wall portions 64 is widened. Therefore, by continuing to apply the pressing force F, the rotation support shafts 46 corresponding to the individual bearing holes 36. Is inserted. After that, by releasing the pressing force F, the main plate portion 62 is elastically restored to the original flat plate shape, the opposing wall portions 64 are returned to the normal positions parallel to each other, and the rotation support of each link member 16 is restored. The shaft 46 is stably supported in the bearing hole 36 of the link support member 34.

  In the above assembling operation, the link members 16 may be sequentially assembled to the link support member 34 one by one, or the pair of link members 16 may be assembled to the link support member 34 at the same time. In the latter case, for example, a pair of link members 16 in which the teeth 48 and 50 are engaged with each other on the base portion 12 are arranged in a flat state (FIG. 5) at the time of a keystroke operation, and links are made from above the link members 16. The support member 34 can be assembled by pressing. In addition, the link support member 34 is configured so that the pair of rotation support shafts 46 of each link member 16 can be smoothly inserted between the opposing wall portions 64 and can be accurately inserted into the corresponding bearing holes 36. As shown in FIG. 3, it is advantageous to have a guide groove 68 on the inner surface of each opposing wall portion 64 on the side adjacent to the main plate portion 62.

  After the link support member 34 is assembled to the pair of link members 16 in this way, the key top 14 is attached to the link support member 34. For this purpose, the inner surface 14b of the key top 14 is provided with a plurality of claws 70 that hold the link support member 34 in a fixed position on the inner surface 14b (see FIG. 7). The claws 70 project upright from the inner surface 14b of the key top 14, and detachably engage with the outer edge region of the main plate portion 62 of the link support member 34 at the flange portions 70a at the respective ends. In the assembling process of the key switch device 10, the main plate portion 62 of the link support member 34 is pressed by covering the key support 14 from above with the link support member 34 assembled to the pair of link members 16 in a flat state. It can be engaged with the plurality of claws 70 in a snap manner while being slightly elastically deformed.

  Here, as shown in FIG. 7, the main plate portion 62 of the link support member 34 is horizontally horizontal from the other edge that does not have the facing wall portion 64, as shown in FIG. An extension portion 72 can be provided. By adopting a configuration in which the claw 70 is engaged with the extended portion 72, for example, when an external force is applied to the outer edge 14c of the key top 14 so as to be separated from the base portion 12, the force point P1 (outer edge 14c) and the fulcrum P2 ( The ratio of the distance between the fulcrum P2 and the action point P3 (the claw 70 on the side close to the force point P1) with respect to the distance to the bearing hole 36) far from the force point P1 is the force point (key top outer edge) in the conventional key switch device. It becomes larger than the ratio of the distance between the fulcrum and the action point (the rotation support part on the side close to the force point) with respect to the distance to the fulcrum (the rotation support part on the side far from the force point). As a result, for the external force of the same magnitude, in the key switch device 10, the force generated at the action point P3 (that is, the force for detaching the claw 70 on the side close to the force point P1) from the main plate portion 62 is reduced. Detachment of the key top 14 from the member 34 or damage to the claw 70 associated therewith is further effectively prevented.

  As shown in FIG. 7, the plurality of claws 70 provided on the inner surface 14 b of the key top 14 cooperate with each other at positions facing each other in the direction perpendicular to the rotation axis 52 (FIG. 1) of each link member 16. Thus, a pair of claws 70 that hold the link support member 34 fixedly can be installed (two pairs of claws 70 are provided in the figure). Alternatively, as shown in FIG. 8A, the plurality of claws 70 are linked in cooperation with each other at positions facing each other in a direction parallel to the rotation axis 52 (FIG. 1) of each link member 16. It can also comprise so that a pair of nail | claw 70 which hold | maintains the member 34 fixedly may be installed (in the figure, two pairs of claws 70 are provided in total). Further, as shown in FIG. 8B, a total of four pairs of claws 70 are provided at positions facing each other in a direction perpendicular to the rotation axis 52 (FIG. 1) of each link member 16 and a parallel direction. You can also. The arrangement and the number of the claws 70 can be optimized in consideration of the dimensions of the key top 14, the position on the outer edge 14c of the key top 14 that tends to become the above-mentioned power point during operation, and the like.

  The configuration of the link support member 34 and the claw 70 of the key top 14 related thereto is not limited to the illustrated key switch device 10, and is suitable for a key switch device having a conventional structure that does not have the protective member 56, for example. Is applicable. Even in such a configuration, a key switch device excellent in operability and structural reliability capable of avoiding unexpected key top dropout is provided.

  9 and 10 show a key switch device 80 according to the related art of the present invention. The key switch device 80 includes substantially the same components as the components of the key switch device 10 according to the above-described embodiment of the present invention. Description is omitted.

  The key switch device 80 includes a base 82, a key top 86 disposed above the base 82 and having a light-transmitting symbol area 84, and a key top 86 in the ascending / descending direction relative to the base 82 (that is, substantially A pair of link members 16 that are guided and supported in the vertical direction), a switch member 20 having a contact portion 18 that opens and closes in response to the raising and lowering operation of the key top 86, and a symbol region 84 of the key top 86 provided on the base 82. And a light emitting unit 88 that emits the transmitted light L. Further, the key switch device 80 applies an elastic biasing force in the upward direction (that is, initial position returning force) to the key top 86 and opens and closes the contact portion 18 of the switch member 20 in response to the lifting and lowering operation of the key top 86. A biasing member 22 is provided. The key top 86 can be moved up and down while maintaining a predetermined posture in the vertical direction with respect to the base 82 when the pair of link members 16 are interlocked with each other.

  In addition to the first and second support plates 24 and 26 of the base 12 in the key switch device 10 described above, the base portion 82 includes a circuit board 90 placed on the upper surface 24a of the first support plate 24, and the circuit board 90 It has a laminated structure including a third support plate 92 placed on the upper surface 90 a and a fourth support plate 94 placed on the upper surface 92 a of the third support plate 92. The circuit board 90 has a configuration of, for example, a flexible circuit board, and an LED (light emitting diode: not shown) serving as a light source of the light emitting unit 88 is mounted at a desired position (center in the figure). In addition, as a light source of the light emission part 88, various light emitting elements, such as an organic EL element, are employable instead of LED.

  The third support plate 92 is a thin plate made of metal or resin, and a light emitting portion 88 is formed at a position below the key top 14. For example, when the LED mounted on the circuit board 90 is present at the position of the light emitting unit 88, the light emitting unit 88 has a through hole, a network structure, and a transparent structure that can transmit light emitted from the LED substantially without obstacles. An area or the like is formed on the third support plate 92. Further, when the LED mounted as the light source on the circuit board 90 exists at a position away from the key switch device 10, the third support plate 92 is configured as a light guide plate made of a resin material having a desired light guide property. Is done. In this case, the light emitting unit 88 has a dot pattern-like reflection that can change the traveling direction of the light propagated from the LED of the light source through the third support plate 92 that is the light guide plate to the direction toward the key top 14. A structure is provided.

  The fourth support plate 94 holds the membrane switch sheet 54 constituting the switch member 20 on the third support plate 92 in cooperation with the second support plate 26. In the fourth support plate 94, an opening 96 is formed at a position overlapping the light emitting unit 88 so as not to hinder the progress of light emitted from the light emitting unit 88 provided on the third support plate 92. Since the opening 96 is disposed at a position overlapping the contact 18 formed on the membrane switch sheet 54, a plurality of openings 96 are actually provided so that the contact 18 can be supported on the back surface when the key top 14 is pressed. Can include beams and struts. The membrane switch sheet 54 is formed to be transparent or translucent so that at least a portion overlapping the opening 96 of the fourth support plate 94 does not hinder the progress of light emitted from the light emitting unit 88.

  Similar to the key top 14 in the key switch device 10 described above, the key top 86 has an operation surface 86a and an inner surface 86b. In the key top 86, the link support member 34 described above is not used, and a rotation support portion 98 that rotatably receives the second end (upper end) region of each link member 16 is formed at a predetermined position on the inner surface 86b. The The rotation support part 98 has a bearing hole (not shown) made of a through hole with a notch, for example. Instead of this configuration, the link support member 34 may be attached to the inner surface 86 b of the key top 86 as in the key switch device 10.

  The key top 86 is preferably integrally molded from a transparent or translucent resin material having light transmittance, and a surface of a desired color is applied to the surface of the key top 86, and a dark color such as black is further formed on the surface. A top coat is applied. Then, a desired symbol region 84 such as a character or a code is formed by locally removing a desired portion of the top coat by a character insertion process using a laser, for example. The symbol area 84 obtained in this way allows the light L emitted from the light emitting portion 88 to be transmitted from the inner surface 86b of the key top 86 to the operation surface 86a.

  The urging member 22 is disposed between the key top 86 and the membrane switch sheet 54 in the same manner as the urging member 22 in the key switch device 10 described above. That is, the urging member 22 is arranged in the middle of the propagation path of the light L from the light emitting unit 88 to the symbol region 84. Therefore, the urging member 22 is formed of a transparent or translucent material that can transmit the light L. As a result, the light L emitted from the light emitting unit 88 passes through the biasing member 22 and reliably reaches the symbol region 84 of the key top 86.

  In the key switch device 80, similarly to the key switch device 10 described above, when no external force is applied to the key top 86, the urging member 22 is at the dome top portion 22a and the stroke upper limit position where the key top 86 is separated from the base portion 12 vertically upward. (Fig. 9). At this time, the membrane switch sheet 54 is in a state where the contact portion 18 is opened. Further, when the key top 86 is pushed down by the keystroke operation, the urging member 22 is elastically deformed as the key top 86 is lowered, and an upward elastic urging force (initial position returning force) is applied to the key top 86. In addition, when the key top 86 reaches the stroke lower limit position, the contact portion 18 is closed by pressing the membrane switch sheet 54 from the outside with the protrusion 22c on the inner surface (FIG. 10). When the pressing force to the key top 86 is released, the urging member 22 is elastically restored to return the key top 86 to the upper limit position, and the membrane switch sheet 54 is restored to open the contact portion 18. The

  The key switch device 80 efficiently reaches the symbol region 84 with the light L emitted from the light emitting portion 88 in a structure (a so-called backlight structure) that illuminates the symbol region 84 of the key top 86 such as characters and signs from the inside of the key. It has an internal shading function to make it happen. More specifically, the key switch device 80 includes a light shielding member 100 that is inserted and disposed between the base 82 and the key top 86 at a position that does not hinder the propagation of the light L from the light emitting unit 88 to the symbol region 84. The light shielding member 100 is a rubber annular element that can be elastically deformed in accordance with the downward movement of the key top 86, and is elastically deformed between the base 82 and the key top 86 following the upward and downward movement of the key top 86. Thus, the posture in which the pair of link members 16, the contact portion 18 of the switch member 20, and the biasing member 22 are always surrounded is maintained. Thereby, the light shielding member 100 reliably and stably prevents leakage of the light L through the gap between the base portion 82 and the key top 86 to the outside of the switch during the raising / lowering operation of the key top 14 (FIGS. 9 and FIG. 9). 10).

  The light shielding member 100 has the same configuration as the protective member 56 in the key switch device 10 described above. That is, the light shielding member 100 includes a cylindrical portion 102 having a substantially rectangular shape in plan view that exhibits a main light shielding function for the light L, and a sheet-like portion 104 connected to one end (lower end in the drawing) of the cylindrical portion 102. The cylindrical portion 102 is provided with a step 102a whose radial dimension changes locally at an intermediate position in the height direction. The sheet-like portion 104 is formed with an opening 104 a that communicates with the internal space of the tubular portion 102. Further, the light shielding member 100 is formed so that at least the cylindrical portion 102 has a light-impermeable color so that the leakage of the light L can be reliably prevented.

  The cylindrical portion 102 and the sheet-like portion 104 of the light shielding member 100 can be integrally formed with each other, or can be formed as separate members and fixed to each other with an adhesive or the like (FIGS. 9 and 10). The light shielding member 100 is shown in which the separate cylindrical portion 102 and sheet-like portion 104 are fixed to each other). In addition, the sheet-like portion 104 of the light shielding member 100 is provided with an annular protrusion 106 for preventing an external force such as pulling away from the base 82 from being unintentionally applied to the outer edge 86 c of the key top 86. It can also be installed with a space from the outer edge 86c. Also in this case, as shown in the figure, the separate protrusion 106 may be fixed to the sheet-like portion 104 with an adhesive or the like, or the protrusion 106 and the sheet-like portion 104 may be integrally formed.

  In the key switch device 80 having the above-described configuration, the light shielding member 100 is a member separate from the urging member 22 that is a rubber element that similarly elastically deforms following the ascending / descending operation of the key top 86. Therefore, it is possible to prepare a light shielding member 100 having an optimum characteristic capable of exhibiting a required level of light leakage prevention function. Therefore, in order to be suitably used for a low-profile keyboard, as a guide structure for the key top 86, a pair of link members 16 that interlock with each other about the interconnection portion (the teeth 48 and 50 in the illustrated embodiment) are opened and closed. In the key switch device 80 provided, a high-level internal light shielding function that can reliably and stably prevent the backlight light L from leaking outside through the gap between the base portion 82 and the key top 86 is ensured. As a result, the key switch device 80 with excellent operability and structural reliability that can efficiently improve the visibility of the symbol region 84 by causing the light L emitted from the light emitting unit 88 to efficiently reach the symbol region 84. Provided. Further, since the key switch device 80 can be configured only by adding the light shielding member 100 to the conventional low-profile and backlight structure key switch device, an increase in manufacturing cost can be suppressed.

  The light shielding member 100 is easily deformed by accurately following the raising / lowering operation of the key top 86 without substantially affecting the sense of keystroke operation given by the elastic biasing force of the biasing member 22 applied to the keytop 86. It is very advantageous to have the following characteristics: In this case, the initial position returning operation of the key top 86 is substantially controlled by the elastic restoring force generated by the biasing member 22. Such characteristics of the light shielding member 100 are obtained mainly depending on attributes such as the shape, size, and material of the cylindrical portion 102. According to this configuration, even though the light shielding member 100 is interposed between the base portion 82 and the key top 86, the influence on the keystroke operation characteristics of the key switch device 80 is eliminated (that is, the operator can operate in the operational manner). A high level of light blocking function against backlight light can be secured.

  In the light shielding member 100, the lower end of the cylindrical portion 102 and the sheet portion 104 are in contact with the upper surface 26 a of the second support plate 26 outside the pair of sliding support portions 30 provided on the second support plate 26 of the base 82. (Fig. 9). As a result, the light shielding member 100 slidably supports the opening 28 (FIG. 1) of the second support plate 26 of the base 82 for disposing the biasing member 22 adjacent to the switch member 20 and the link member 16. The sliding support portion 30 (especially the guide groove 32) of the second support plate 26 of the base portion 82 of the base 82 is always surrounded during the raising / lowering operation of the key top 14, and the light L diffused through them leaks out of the key. Make sure to prevent it.

  Further, it is advantageous that the light shielding member 100 is placed in a state of receiving an initial pressure from the base portion 82 and the key top 86 when the key top 86 is in the upper limit position of the above-described lifting operation. According to such a configuration, even when the key switch device 80 is not used, the light shielding member 100 is held in a state of being slightly elastically deformed between the base portion 82 and the key top 86, and in particular, the sheet-like portion 104. Is prevented from floating or turning up with respect to the base portion 82, and a problem that the light L from the light emitting portion 88 leaks between the sheet-like portion 104 and the base portion 82 is avoided.

  The light shielding member 100 described above can be suitably applied not only to the illustrated key switch device 80 but also to a conventional key switch device having a so-called pantograph-type link member, for example. Even in such a configuration, there is provided a key switch device excellent in operability and structural reliability, which has an internal light shielding function that allows backlight light to efficiently reach the symbol area of the key top.

  FIG. 11 is a schematic exploded view showing main components of a keyboard 110 according to an embodiment of the present invention, in which a plurality of the key switch devices 10 or the key switch devices 80 described above are arranged in a predetermined arrangement. The keyboard 110 has a low-profile structure that can be used as an input device of a portable electronic device such as a notebook or palmtop personal computer. In the keyboard 110, the base portions 12 and 82 in the key switch devices 10 and 80 and the membrane switch sheet 54 of the switch member 20 are common to all the key switch devices 10 and 80 incorporated in the keyboard 110, respectively. 12 ', 82' and membrane switch sheet 54 '. Further, the sheet-like portions 60 and 104 of the protection member 56 or the light shielding member 100 in the key switch devices 10 and 80 are formed as large sheet members 60 ′ and 104 ′ that are common to all the key switch devices 10 and 80. ing. In each of the key switch devices 10 and 80, a link support member 34 attached to the key tops 14 and 86 is employed. The keyboard 110 having such a configuration has a low profile and is excellent in operability and structural reliability.

  As shown in FIG. 12, in the keyboard 110, the protective members 56 of the individual key switch devices 10 and 80 or the cylindrical portions 58 and 102 of the light shielding member 100 are integrated in advance with large sheet members 60 'and 104'. A molded configuration can be employed. In other words, in this case, the protection member 56 or the light shielding member 100 of each of the plurality of key switch devices 10, 80 has integrally the sheet members 60 ′, 104 ′ extending in a range including the key switch devices 10, 80. become.

  Alternatively, as shown in FIG. 13, the cylindrical members 58 and 102 of the protective member 56 or the light shielding member 100 and the large sheet members 60 'and 104' included in the individual key switch devices 10 and 80 are separately molded in advance. (FIG. 13 (a)), it is possible to adopt a configuration in which the cylindrical portions 58 and 102 are fixed to the sheet members 60 ′ and 104 ′ with an adhesive or the like (FIG. 13 (b)) in a subsequent process. That is, in this case, the protective member 56 or the light shielding member 100 of each of the plurality of key switch devices 10 and 80 is applied to the sheet members 60 ′ and 104 ′ extending in a range including the key switch devices 10 and 80 by an adhesive or the like. It becomes fixed.

It is a disassembled perspective view which shows the key switch apparatus by one Embodiment of this invention. FIG. 2 is an assembled cross-sectional view showing the key switch device of FIG. 1 in a non-operating state. It is an expansion perspective view which shows the link support member used with the key switch apparatus of FIG. 1 from the downward direction. It is an expansion perspective view which shows a pair of link member used with the key switch apparatus of FIG. 1 from the downward direction. FIG. 2 is an assembled cross-sectional view showing the key switch device of FIG. 1 in a state during a keystroke operation. It is a figure explaining the effect | action of the link support member in the key switch apparatus of FIG. 1, (a) The state before connecting a link member and (b) The state in the middle of connecting a link member are each typically shown. FIG. It is a disassembled perspective view which shows the modification of the link support member in the key switch apparatus of FIG. 1 from a lower part with a keytop and a link member. It is the perspective view which shows (a) 1st modification of the key top of FIG. 7, and (b) 2nd modification from the downward direction, respectively. It is assembly sectional drawing which shows the key switch apparatus which concerns on the related technology of this invention in the state at the time of non-operation. FIG. 10 is an assembled cross-sectional view showing the key switch device of FIG. 9 in a state when a key is pressed. It is a disassembled perspective view which shows a part of main component of the keyboard by one Embodiment of this invention. It is sectional drawing of the protection member / light-shielding member used with the keyboard of FIG. It is sectional drawing of the protection member / light-shielding member by a modification, (a) The state before an assembly and (b) The state after an assembly are each shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10, 80 Key switch apparatus 12, 82 Base 14, 86 Key top 16 Link member 18 Contact part 20 Switch member 22 Energizing member 30 Sliding support part 34 Link support member 36 Bearing hole (rotation support part)
44 Sliding support shaft 46 Rotating support shaft 48, 50 Teeth 54 Membrane switch sheet 56 Protection member 84 Symbol area 88 Light emitting portion 100 Light shielding member 110 Keyboard 60 ', 104' Sheet member

Claims (9)

A base, a key top disposed above the base, a pair of link members that link and support the key top with respect to the base in the ascending / descending direction, and open / close corresponding to the ascending / descending operation of the key top In a key switch device comprising: a switch member having a contact portion to perform; and an urging member that applies an elastic urging force in the upward direction to the key top.
The pair of link members, the contact portions, and the biasing member are inserted between the base portion and the key top at a position surrounding the pair of link members, and the pair of link members are deformed following the lifting operation of the key top. A protective member for protecting the link member, the contact portion and the biasing member from intrusion of foreign matter,
A key switch device characterized by.   The said protection member has the characteristic which deform | transforms following the said raising / lowering operation | movement of the said keytop, without affecting the keystroke operation feeling obtained by the said elastic biasing force of the said biasing member. Key switch device.   The base portion has a sliding support portion that slidably supports each of the pair of link members, and the protective member is in contact with the upper surface of the base portion at the lower end thereof, and the sliding support portion is made a foreign object. The key switch device according to claim 1, wherein the key switch device is protected from intrusion.   The key top includes a rotation support portion that rotatably supports each of the pair of link members, and the protection member contacts an inner surface of the key top at an upper end thereof, and the rotation support portion The key switch device according to claim 1, wherein the key switch device is protected from intrusion of foreign matter.   5. The protective member according to claim 1, wherein the protective member is placed in a state of receiving an initial pressure from the base and the key top when the key top is at an upper limit position of the lifting / lowering operation. Key switch device.   The switch member includes a membrane switch sheet that supports the contact portion at a position below the key top and is disposed adjacent to the base, and the biasing member is disposed between the key top and the membrane switch sheet. And is elastically deformed as the key top descends to generate the elastic urging force. The key switch device according to claim 1, wherein the key switch device is closed.   Each of the pair of link members includes gears meshing with each other at one end region, and a rotation support shaft rotatably connected to the key top. The key switch device according to any one of claims 1 to 6, further comprising a sliding support shaft slidably engaged with the base portion. A keyboard configured by arranging a plurality of key switch devices according to any one of claims 1 to 7,
The protective member of each of the plurality of key switch devices integrally includes a sheet member extending in a range including the key switch devices;
Keyboard characterized by. A keyboard configured by arranging a plurality of key switch devices according to any one of claims 1 to 7,
The protective member of each of the plurality of key switch devices is fixed to a sheet member extending in a range including the key switch devices;
Keyboard characterized by.

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